Valves have been used for centuries in many different ways to control the flow of fluids/gases. With the progress of fluid technology especially since the industrial revolution, a great variety of uses have been found for valves. Some of these uses may include pneumatic and motor-driven actuation with controllers that are regulated by a computer. By and large, however, the basic flow design of valves has stayed relatively constant along some of these basic lines as mentioned below.
Currently, various types of valves are in use. One such valve is a gate valve. The gate valve also known as lift valves is a valve that opens by lifting a round or rectangular gate/wedge out of the path of the fluid. The gate valve typically contains a circular disc or a slice known as the gate. The circular disc or slice is mounted perpendicular to the pipe containing the fluid/gas. The reciprocal actuation guides the gate up and down into the seat of the valve to either open the flow path for full flow or to close it down.
Another valve that is in use is a globe valve. The globe valves are very good at throttling, but with reduced flow capabilities. The path of the fluid through the globe valve is tortuous, and as a result, these valves do not allow as much fluid flow for a given size as the other basic valve designs.
Yet another kind of valve in use is a ball valve, which is most popular today. In the ball valve, the valve actuator is connected by a valve stem to a ball inside the valve. The ball has a large hole bored inside of it from one side to the other. Rotating the ball allows for this hole to be aligned with the incoming and outgoing flow path. In the closed position, the ball opening is rotated perpendicular to the flow path and completely shuts off the flow of fluid.
One more type of valve in use presently is a check valve. A typical example of a check valve is a diaphragm check valve which uses a flexing rubber diaphragm positioned to create a normally-closed valve. Pressure on the upstream side must be greater than the pressure on the downstream side by a certain amount, known as the pressure differential, for the check valve to open allowing flow. Once positive pressure stops, the diaphragm automatically flexes back to its original closed position. Pressure on the upstream side must be greater than the pressure on the downstream side by a certain amount, known as the pressure differential, for the check valve to open for allowing flow. Once positive pressure stops, the diaphragm automatically flexes back to its original closed position.
All the above mentioned valves have disadvantage that they have resistance in the flow because of change in direction of the flow. For example, in the ball valve or the gate valve, the angle of flow is shifted when the valve is not fully open.
Accordingly, there exists a need to provide a flow controlling device which overcomes the above mentioned drawbacks of the prior art.